1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
|
# Copyright 2012 Google Inc.
#
# http://www.logilab.fr/ -- mailto:contact@logilab.fr
# This program is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free Software
# Foundation; either version 2 of the License, or (at your option) any later
# version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details
#
# You should have received a copy of the GNU General Public License along with
# this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
"""Checkers for various standard library functions."""
import re
import sys
import astroid
from astroid.bases import Instance
from pylint.interfaces import IAstroidChecker
from pylint.checkers import BaseChecker
from pylint.checkers import utils
_VALID_OPEN_MODE_REGEX = re.compile(r'^(r?U|[rwa]\+?b?)$')
if sys.version_info >= (3, 0):
OPEN_MODULE = '_io'
else:
OPEN_MODULE = '__builtin__'
class StdlibChecker(BaseChecker):
__implements__ = (IAstroidChecker,)
name = 'stdlib'
msgs = {
'W1501': ('"%s" is not a valid mode for open.',
'bad-open-mode',
'Python supports: r, w, a modes with b, +, and U options. '
'See http://docs.python.org/2/library/functions.html#open'),
'W1502': ('Using datetime.time in a boolean context.',
'boolean-datetime',
'Using datetetime.time in a boolean context can hide '
'subtle bugs when the time they represent matches '
'midnight UTC. This behaviour was fixed in Python 3.5. '
'See http://bugs.python.org/issue13936 for reference.',
{'maxversion': (3, 5)}),
}
@utils.check_messages('bad-open-mode')
def visit_callfunc(self, node):
"""Visit a CallFunc node."""
if hasattr(node, 'func'):
infer = utils.safe_infer(node.func)
if infer and infer.root().name == OPEN_MODULE:
if getattr(node.func, 'name', None) in ('open', 'file'):
self._check_open_mode(node)
@utils.check_messages('boolean-datetime')
def visit_unaryop(self, node):
if node.op == 'not':
self._check_datetime(node.operand)
@utils.check_messages('boolean-datetime')
def visit_if(self, node):
self._check_datetime(node.test)
@utils.check_messages('boolean-datetime')
def visit_ifexp(self, node):
self._check_datetime(node.test)
@utils.check_messages('boolean-datetime')
def visit_boolop(self, node):
for value in node.values:
self._check_datetime(value)
def _check_datetime(self, node):
""" Check that a datetime was infered.
If so, emit boolean-datetime warning.
"""
try:
infered = next(node.infer())
except astroid.InferenceError:
return
if (isinstance(infered, Instance) and
infered.qname() == 'datetime.time'):
self.add_message('boolean-datetime', node=node)
def _check_open_mode(self, node):
"""Check that the mode argument of an open or file call is valid."""
try:
mode_arg = utils.get_argument_from_call(node, position=1, keyword='mode')
if mode_arg:
mode_arg = utils.safe_infer(mode_arg)
if (isinstance(mode_arg, astroid.Const)
and not _VALID_OPEN_MODE_REGEX.match(mode_arg.value)):
self.add_message('bad-open-mode', node=node,
args=(mode_arg.value))
except (utils.NoSuchArgumentError, TypeError):
pass
def register(linter):
"""required method to auto register this checker """
linter.register_checker(StdlibChecker(linter))
|
